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1.  Acetabular Paralabral Cyst as a Rare Cause of Obturator Neuropathy: A Case Report 
Annals of Rehabilitation Medicine  2014;38(3):427-432.
An acetabular paralabral cyst is a benign soft tissue cyst usually seen in association with a tear of the acetabular labrum. Acetabular paralabral cysts are often the cause of joint pain, but they rarely cause compression of the adjacent neurovascular structures. We present a case of a 63-year-old male patient who had paresis and atrophy of right hip adductor muscles. Right obturator neuropathy was confirmed through an electrodiagnostic study. In addition, magnetic resonance imaging showed a paralabral cyst in the right acetabulum which extended to the pelvic wall. The patient underwent conservative treatment without surgical procedure. The pain was decreased after 1 month of conservative therapy. The pain was decreased at the 1-month follow-up. Follow-up electromyography showed polyphasic motor unit potentials in adductor magnus and adductor longus muscles. Based on the experience of this case, an acetabular paralabral cyst should be considered as one of the rare causes of obturator neuropathy.
PMCID: PMC4092188  PMID: 25024971
Acetabulum; Synovial cyst; Obturator nerve
2.  Disease-specific Growth Charts of Marfan Syndrome Patients in Korea 
Journal of Korean Medical Science  2015;30(7):911-916.
Patients with Marfan syndrome (MFS) presents with primary skeletal manifestations such as tall stature, chest wall abnormality, and scoliosis. These primary skeletal manifestations affect the growth pattern in MFS. Therefore, it is not appropriate to use normal growth charts to evaluate the growth status of MFS. We aimed to develop disease-specific growth charts for Korean MFS patients and to use these growth charts for understanding the growth patterns in MFS and managing of patients with MFS. Anthropometric data were available from 187 males and 152 females with MFS through a retrospective review of medical records. Disease-specific growth charts were generated and 3, 25, 50, 75, and 97 percentiles were calculated using the LMS (refers to λ, μ, and σ, respectively) smoothing procedure for height and weight. Comparisons between MFS patients and the general population were performed using a one-sample t-test. With regard to the height, the 50th percentile of MFS is above the normative 97th percentile in both genders. With regard to the weight, the 50 percentile of MFS is above the normative 75th percentile in male and between the normative 50th percentile and the 75th percentile in female. The disease-specific growth charts for Korean patients with MFS can be useful for monitoring growth patterns, planning the timing of growth-reductive therapy, predicting adult height and recording responses to growth-reductive therapy.
PMCID: PMC4479945  PMID: 26130954
Marfan Syndrome; Growth Charts; Body Height; Body Weight
3.  Multivariate Analysis of Risk Factors Associated With the Nonreversal Ileostomy Following Sphincter-Preserving Surgery for Rectal Cancer 
Annals of Coloproctology  2015;31(3):98-102.
A loop ileostomy is used to protect an anastomosis after anal sphincter-preserving surgery, especially in patients with low rectal cancer, but little information is available concerning risk factors associated with a nonreversal ileostomy. The purpose of this study was to identify risk factors of ileostomy nonreversibility after a sphincter-saving resection for rectal cancer.
Six hundred seventy-nine (679) patients with rectal cancer who underwent sphincter-preserving surgery between January 2004 and December 2011 were evaluated retrospectively. Of the 679, 135 (19.9%) underwent a defunctioning loop ileostomy of temporary intent, and these patients were divided into two groups, that is, a reversal group (RG, 112 patients) and a nonreversal group (NRG, 23 patients) according to the reversibility of the ileostomy.
In 23 of the 135 rectal cancer patients (17.0%) that underwent a diverting ileostomy, stoma reversal was not possible for the following reasons; stage IV rectal cancer (11, 47.8%), poor tone of the anal sphincter (4, 17.4%), local recurrence (2, 8.7%), anastomotic leakage (1, 4.3%), radiation proctitis (1, 4.3%), and patient refusal (4, 17.4%). The independent risk factors of the nonreversal group were anastomotic leakage or fistula, stage IV cancer, local recurrence, and comorbidity.
Postoperative complications such as anastomotic leakage or fistula, advanced primary disease (stage IV), local recurrence and comorbidity were identified as risk factors of a nonreversal ileostomy. These factors should be considered when drafting prudential guidelines for ileostomy closure.
PMCID: PMC4496460  PMID: 26161377
Sphincter-preserving surgery; Ileostomy; Rectal cancer
5.  Reliability of the Percent Density in Digital Mammography with a Semi-Automated Thresholding Method 
Journal of Breast Cancer  2014;17(2):174-179.
The reliability of the quantitative measurement of breast density with a semi-automated thresholding method (Cumulus™) has mainly been investigated with film mammograms. This study aimed to evaluate the intrarater reproducibility of percent density (PD) by Cumulus™ with digital mammograms.
This study included 1,496 craniocaudal digital mammograms from the unaffected breast of breast cancer patients. One rater reviewed each mammogram and estimated the PD using the Cumulus™ method. All images were reassessed by the same rater 1 month later without reference to the previously assigned values. The repeatability of the PD was evaluated by an intraclass correlation coefficient (ICC). All patients were grouped based on their body mass index (BMI), age, family history of breast cancer, breastfeeding history and breast area (calculated with Cumulus™), and subgroup analysis for the ICC of each group was performed. All patients were categorized by their Breast Imaging Reporting and Data System (BI-RADS) density pattern, and the mean and standard deviation of the PD by each BI-RADS categories were compared.
The ICC for the PD was 0.94, indicating excellent repeatability. The discrepancy between the paired PD values ranged from 0 to 23.93, with an average of 3.90 (standard deviation=3.39). The subgroup ICCs for the PD ranged from 0.88 to 0.96, indicating excellent reliability in all subgroups regardless of patient variables. The ICCs of the PD for the high-risk (BI-RADS 3 and 4) and low-risk (BI-RADS 1 and 2) groups were 0.90 and 0.88, respectively.
This study suggests that PD calculated with digital mammograms has an acceptable reliability regardless of patient age, BMI, family history of breast cancer, breastfeeding history, breast size, and BI-RADS density pattern.
PMCID: PMC4090321  PMID: 25013440
Breast; Mammography; Observer variation
6.  Silencing of KIF14 interferes with cell cycle progression and cytokinesis by blocking the p27Kip1 ubiquitination pathway in hepatocellular carcinoma 
Although it has been suggested that kinesin family member 14 (KIF14) has oncogenic potential in various cancers, including hepatocellular carcinoma (HCC), the molecular mechanism of this potential remains unknown. We aimed to elucidate the role of KIF14 in hepatocarcinogenesis by knocking down KIF14 in HCC cells that overexpressed KIF14. After KIF14 knockdown, changes in tumor cell growth, cell cycle and cytokinesis were examined. We also examined cell cycle regulatory molecules and upstream Skp1/Cul1/F-box (SCF) complex molecules. Knockdown of KIF14 resulted in suppression of cell proliferation and failure of cytokinesis, whereas KIF14 overexpression increased cell proliferation. In KIF14-silenced cells, the levels of cyclins E1, D1 and B1 were profoundly decreased compared with control cells. Of the cyclin-dependent kinase inhibitors, the p27Kip1 protein level specifically increased after KIF14 knockdown. The increase in p27Kip1 was not due to elevation of its mRNA level, but was due to inhibition of the proteasome-dependent degradation pathway. To explore the pathway upstream of this event, we measured the levels of SCF complex molecules, including Skp1, Skp2, Cul1, Roc1 and Cks1. The levels of Skp2 and its cofactor Cks1 decreased in the KIF14 knockdown cells where p27Kip1 accumulated. Overexpression of Skp2 in the KIF14 knockdown cells attenuated the failure of cytokinesis. On the basis of these results, we postulate that KIF14 knockdown downregulates the expression of Skp2 and Cks1, which target p27Kip1 for degradation by the 26S proteasome, leading to accumulation of p27Kip1. The downregulation of Skp2 and Cks1 also resulted in cytokinesis failure, which may inhibit tumor growth. To the best of our knowledge, this is the first report that has identified the molecular target and oncogenic effect of KIF14 in HCC.
PMCID: PMC4044675  PMID: 24854087
cell cycle; cytokinesis; hepatocellular carcinoma; KIF14; p27kip1; ubiquitination
7.  Toxic effects of methylmercury, arsanilic acid and danofloxacin on the differentiation of mouse embryonic stem cells into neural cells 
Journal of Veterinary Science  2014;15(1):61-71.
This study was performed to assess the neurotoxic effects of methylmercury, arsanilic acid and danofloxacin by quantification of neural-specific proteins in vitro. Quantitation of the protein markers during 14 days of differentiation indicated that the mouse ESCs were completely differentiated into neural cells by Day 8. The cells were treated with non-cytotoxic concentrations of three chemicals during differentiation. Low levels of exposure to methylmercury decreased the expression of GABAA-R and Nestin during the differentiating stage, and Nestin during the differentiated stage. In contrast, GFAP, Tuj1, and MAP2 expression was affected only by relatively high doses during both stages. Arsanilic acid affected the levels of GABAA-R and GFAP during the differentiated stage while the changes of Nestin and Tuj1 were greater during the differentiating stage. For the neural markers (except Nestin) expressed during both stages, danofloxacin affected protein levels at lower concentrations in the differentiated stage than the differentiating stage. Acetylcholinesterase activity was inhibited by relatively low concentrations of methylmercury and arsanilic acid during the differentiating stage while this activity was inhibited only by more than 40 µM of danofloxacin in the differentiated stage. Our results provide useful information about the different toxicities of chemicals and the impact on neural development.
PMCID: PMC3973767  PMID: 24136205
arsanilic acid; danofloxacin; embryonic stem cell test; methylmercury; neural cell
8.  Impact of Enzyme Replacement Therapy on Linear Growth in Korean Patients with Mucopolysaccharidosis Type II (Hunter Syndrome) 
Journal of Korean Medical Science  2014;29(2):254-260.
Hunter syndrome (or mucopolysaccharidosis type II [MPS II]) arises because of a deficiency in the lysosomal enzyme iduronate-2-sulfatase. Short stature is a prominent and consistent feature in MPS II. Enzyme replacement therapy (ERT) with idursulfase (Elaprase®) or idursulfase beta (Hunterase®) have been developed for these patients. The effect of ERT on the growth of Korean patients with Hunter syndrome was evaluated at a single center. This study comprised 32 patients, who had received ERT for at least 2 yr; they were divided into three groups according to their ages at the start of ERT: group 1 (<6 yr, n=14), group 2 (6-10 yr, n=11), and group 3 (10-20 yr, n=7). The patients showed marked growth retardation as they got older. ERT may have less effect on the growth of patients with the severe form of Hunter syndrome. The height z-scores in groups 2 and 3 revealed a significant change (the estimated slopes before and after the treatment were -0.047 and -0.007, respectively: difference in the slope, 0.04; P<0.001). Growth in response to ERT could be an important treatment outcome or an endpoint for future studies.
Graphical Abstract
PMCID: PMC3924006  PMID: 24550654
Mucopolysaccharidosis II; Hunter Syndrome; Enzyme Replacement Therapy; Growth; Elaprase; Hunterase
10.  Genotype-phenotype correlation in 27 pediatric patients in congenital adrenal hyperplasia due to 21-hydroxylase deficiency in a single center 
The purpose of the study was to evaluate endocrine patterns of patients with congenital adrenal hyperplasia and each gene mutation and to analyze the correlation between each phenotype and genotype.
This was a retrospective study of the patients with congenital adrenal hyperplasia in the pediatric outpatient clinic at the Samsung Medical Center from November 1994 to December 2012. We analyzed the medical records of 27 patients (male, 19; female, 8) with congenital adrenal hyperplasia who had been diagnosed by genetic testing to have 21-hydroxylase deficiency.
In genetic analysis of 54 alleles from 27 patients, 13 types of mutations were identified. The distribution of 21-hydroxylase deficiency gene mutations revealed that intron 2 splice site (c.293-13A/C>G) mutations and large deletions were the most common, at 31.5% and 22.2% respectively, followed by p.I173N, p.R356W, and p.I172N mutations at 11.1%, 9.3%, and 9.3%, respectively. Other mutations were observed at 1.9-3.7%. No novel mutations were detected.
The analysis of 54 alleles revealed 13 types of mutation. The salt wasting form showed a good correlation between genotype and phenotype, but the simple virilizing and nonclassic forms showed inconsistencies between genotype and phenotype. The distribution of CYP21A2 mutations was evaluated for 21-hydroxylase deficiency patients from a single center. This study provides limited data on mutation spectrum and genotype-phenotype correlation of 21-hydroxylase deficiency in Korea.
PMCID: PMC4027076  PMID: 24904866
21 hydroxylase deficiency; Human CYP21A2 protein; Genotype; Phenotype
11.  Development of a monoclonal antibody against deoxynivalenol for magnetic nanoparticle-based extraction and an enzyme-linked immunosorbent assay 
Journal of Veterinary Science  2013;14(2):143-150.
Monoclonal antibody (mAb, NVRQS-DON) against deoxynivalenol (DON) was prepared. DON-Ag coated enzyme linked immunosorbent assay (ELISA) and DON-Ab coated ELISA were prepared by coating the DON-BSA and DON mAb. Quantitative DON calculation ranged from 50 to 4,000 ng/mL for DON-Ab coated ELISA and from 25 to 500 ng/mL for DON-Ag coated ELISA. 50% of inhibitory concentration values of DON, HT-2, 15-acetyl-DON, and nivalenol were 23.44, 22,545, 5,518 and 5,976 ng/mL based on the DON-Ab coated ELISA. Cross-reactivity levels of the mAb to HT-2, 15-acetyl-DON, and nivalenol were 0.1, 0.42, and 0.40%. The intra- and interassay precision coefficient variation (CV) were both <10%. In the mAb-coated ELISA, mean DON recovery rates in animal feed (0 to 1,000 µg/kg) ranged from 68.34 to 95.49% (CV; 4.10 to 13.38%). DON in a buffer solution (250, 500 and 1,000 ng/mL) was isolated using 300 µg of NVRQS-DON and 3 mg of magnetic nanoparticles (MNPs). The mean recovery rates of DON using this mAb-MNP system were 75.2, 96.9, and 88.1% in a buffer solution spiked with DON (250, 500, and 1,000 ng/mL). Conclusively we developed competitive ELISAs for detecting DON in animal feed and created a new tool for DON extraction using mAb-coupled MNPs.
PMCID: PMC3694185  PMID: 23388439
deoxynivalenol; ELISA; magnetic nanoparticles; monoclonal antibody
12.  Phase I/II clinical trial of enzyme replacement therapy with idursulfase beta in patients with mucopolysaccharidosis II (Hunter Syndrome) 
Mucopolysaccharidosis II (MPS II, Hunter syndrome) is a rare X-linked lysosomal storage disorder caused by the deficiency of iduronate-2-sulfatase (IDS). In affected patients, glycosaminoglycan (GAG) accumulates in the lysosomes of many organs and tissues contributing to the pathology associated with MPS II. The objective of this phase I/II clinical study was to evaluate the efficacy and safety of recombinant human iduronate-2-sulfatase (idursulfase beta, Hunterase®) in the treatment of MPS II.
Thirty-one MPS II patients between 6 and 35 years of age were enrolled in a randomized, single-blinded, active comparator-controlled phase I/II trial for 24 weeks. Patients were randomized to active comparator infusions (N=11), 0.5 mg/kg idursulfase beta infusions (N=10), or 1.0 mg/kg idursulfase beta infusions (N=10). The primary efficacy variable was the level of urinary GAG excretion. The secondary variables were changes in the distance walked in 6 minutes (6-minute walk test, 6MWT), echocardiographic findings, pulmonary function tests, and joint mobility.
Patients in all three groups exhibited reduction in urine GAG and this reduced GAG level was maintained for 24 weeks. Urine GAG was also significantly reduced in the 0.5 mg/kg and 1.0 mg/kg idursulfase beta groups when compared to the active comparator group (P = 0.043, 0.002, respectively). Changes in 6MWT were significantly greater in the 0.5 mg/kg and 1.0 mg/kg idursulfase groups than in the active comparator group (p= 0.003, 0.015, respectively). Both idursulfase beta infusions were generally safe and well tolerated, and elicited no serious adverse drug reactions. The most frequent adverse events were urticaria and skin rash, which were easily controlled with administration of antihistamines.
This study indicates that idursulfase beta generates clinically significant reduction of urinary GAG, improvements in endurance as measured by 6MWT, and it has an acceptable safety profile for the treatment of MPS II.
Trial registration NCT01301898
PMCID: PMC3614543  PMID: 23497636
Mucopolysaccharidosis II; Hunter syndrome; ERT; Recombinant iduornate-2-sulfatase; Idursulfase beta
13.  Diagnosis and constitutional and laboratory features of Korean girls referred for precocious puberty 
Korean Journal of Pediatrics  2012;55(12):481-486.
Precocious puberty is defined as breast development before the age of 8 years in girls. The present study aimed to reveal the diagnosis of Korean girls referred for precocious puberty and to compare the constitutional and endocrinological features among diagnosis groups.
The present study used a retrospective chart review of 988 Korean girls who had visited a pediatric endocrinology clinic from 2006 to 2010 for the evaluation of precocious puberty. Study groups comprised fast puberty, true precocious puberty (PP), pseudo PP, premature thelarche, and control. We determined the height standard deviation score (HSDS), weight standard deviation score (WSDS), and body mass index standard deviation score (BMISDS) of each group using the published 2007 Korean growth charts. Hormone tests were performed at our outpatient clinic.
The PP groups comprised fast puberty (67%), premature thelarche (17%), true PP (15%), and pseudo PP (1%). Advanced bone age and levels of estradiol, basal luteinizing hormone (LH), and peak LH after gonadotropin-releasing hormone stimulation testing were significantly high in the fast puberty and true PP groups compared with the control group. HSDS, WSDS, and BMISDS were significantly higher in the true PP group than in the control group (P<0.05).
The frequent causes of PP were found to be fast puberty, true PP, and premature thelarche. Furthermore, BMISDS were significantly elevated in the true PP group. Therefore, we emphasize the need for regular follow-up of girls who are heavier or taller than others in the same age group.
PMCID: PMC3534162  PMID: 23300504
Precocious puberty; Puberty; Premature thelarche; Body mass index; Sexual maturation
14.  Expression of intestinal transporter genes in beagle dogs 
This study was performed to produce a transcriptional database of the intestinal transporters of beagle dogs. Total RNA was isolated from the duodenum and the expression of various mRNAs was measured using GeneChip® oligonucleotide arrays. A total of 124 transporter genes were detected. Genes for fatty acid, peptide, amino acid and glucose and multidrug resistance/multidrug resistance-associated protein (MDR/MRP) transport were expressed at relatively higher levels than the other transporter types. The dogs exhibited abundant mRNA expression of the fatty acid transporters (fatty acid binding proteins, FABPs) FABP1 and FABP2, the ATP-binding cassettes (ABCs) ABCB1A and ABCC2, the amino acid/peptide transporters SLC3A1 and SLC15A1, the glucose transporters SLC5A1, SLC2A2 and SLC2A5, the organic anion transporter SLC22A9 and the phosphate transporters SLC20A1 and SLC37A4. In mice, a similar profile was observed with high expression of the glucose transporters SLC5A1 and SLC2As, the fatty acid transporters FABP1 and FABP2, the MDR/MRP transporters ABCB1A and ABCC2 and the phosphate transporter SLC37A4. However, the overall data reveal diverse transcriptomic profiles of the intestinal transporters of dogs and mice. Therefore, the current database may be useful for comparing the intestinal transport systems of dogs with those of mice to better evaluate xenobiotics.
PMCID: PMC3524273  PMID: 23251289
gene expression; transporters; intestine; dog
15.  LIN28B polymorphisms are associated with central precocious puberty and early puberty in girls 
Korean Journal of Pediatrics  2012;55(10):388-392.
Single-nucleotide polymorphism (SNP) markers within LIN28B have been reported to be related to the timing of pubertal growth. However, no study has investigated the frequency of genetic markers in girls with precocious puberty (PP) or early puberty (EP). This study aimed to determine the frequency of putative genetic markers in girls with PP or EP.
Genomic DNAs were obtained from 77 and 109 girls that fulfilled the criteria for PP and EP, respectively. The controls in this study were 144 healthy volunteers between 20 and 30 years of age. The haplotypes were reconstructed using 11 SNPs of LIN28B, and haplotype association analysis was performed. The haplotype frequencies were compared. Differences in the clinical and laboratory parameters were analyzed according to the haplotype dosage.
Eleven SNPs in LIN28B were all located in a block that was in linkage disequilibrium. The haplotype could be reconstructed using 2 representative SNPs, rs4946651 and rs369065. The AC haplotype was less frequently observed in the PP group than in the controls (0.069 vs. 0.144, P=0.010). The trend that girls with non-AC haplotypes tended to have earlier puberty onset (P=0.037) was illustrated even in the EP+PP patient group by Kaplan-Meier analysis.
The results of the present study showed that non-AC haplotypes of LIN28B had a significant association with PP in girls.
PMCID: PMC3488615  PMID: 23133486
Single-nucleotide polymorphism; Human LIN28 homolog B; Precocious puberty
16.  Increased HoxB4 Inhibits Apoptotic Cell Death in Pro-B Cells 
HoxB4, a homeodomain-containing transcription factor, is involved in the expansion of hematopoietic stem cells and progenitor cells in vivo and in vitro, and plays a key role in regulating the balance between hematopoietic stem cell renewal and cell differentiation. However, the biological activity of HoxB4 in other cells has not been reported. In this study, we investigated the effect of overexpressed HoxB4 on cell survival under various conditions that induce death, using the Ba/F3 cell line. Analysis of phenotypical characteristics showed that HoxB4 overexpression in Ba/F3 cells reduced cell size, death, and proliferation rate. Moreover, the progression from early to late apoptotic stages was inhibited in Ba/F3 cells subjected to HoxB4 overexpression under removal of interleukin-3-mediated signal, leading to the induction of cell cycle arrest at the G2/M phase and attenuated cell death by Fas protein stimulation in vitro. Furthermore, apoptotic cell death induced by doxorubicin-treated G2/M phase cell-cycle arrest also decreased with HoxB4 overexpression in Ba/F3 cells. From these data, we suggest that HoxB4 may play an important role in the regulation of pro-B cell survival under various apoptotic death environments.
PMCID: PMC3419762  PMID: 22915992
Apoptosis; Ba/F3; Cell cycle arrest; Cell proliferation; HoxB4
17.  Continuous renal replacement therapy in neonates weighing less than 3 kg 
Korean Journal of Pediatrics  2012;55(8):286-292.
Continuous renal replacement therapy (CRRT) is becoming the treatment of choice for supporting critically ill pediatric patients. However, a few studies present have reported CRRT use and outcome in neonates weighing less than 3 kg. The aim of this study is to describe the clinical application, outcome, and complications of CRRT in small neonates.
A retrospective review was performed in 8 neonatal patients who underwent at least 24 hours of pumped venovenous CRRT at the Samsung Medical Center in Seoul, Korea, between March 2007 and July 2010. Data, including demographic characteristics, diagnosis, vital signs, medications, laboratory, and CRRT parameters were recorded.
The data of 8 patients were analyzed. At the initiation of CRRT, the median age was 5 days (corrected age, 38+2 weeks to 23 days), and the median body weight was 2.73 kg (range, 2.60 to 2.98 kg). Sixty-two patient-days of therapy were reviewed; the median time for CRRT in each patient was 7.8 days (range, 1 to 37 days). Adverse events included electrolyte disturbances, catheter-related complications, and CRRT-related hypotension. The mean circuit functional survival was 13.9±8.6 hours. Overall, 4 patients (50%) survived; the other 4 patients, who developed multiorgan dysfunction syndrome, died.
The complications of CRRT in newborns are relatively high. However, the results of this study suggest that venovenous CRRT is feasible and effective in neonates weighing less than 3 kg under elaborate supportive care. Furthermore, for using potential benefit of CRRT in neonates, efforts are required for prolonging filter survival.
PMCID: PMC3433565  PMID: 22977441
Critical illness; Infant; Renal replacement therapy; Treatment outcome
18.  Two Novel Insulin Receptor Gene Mutations in a Patient with Rabson-Mendenhall Syndrome: The First Korean Case Confirmed by Biochemical, and Molecular Evidence 
Journal of Korean Medical Science  2012;27(5):565-568.
Rabson-Mendenhall syndrome (RMS) is a rare syndrome manifested by extreme insulin resistance with hyperinsulinemia, acanthosis nigricans, tooth dysplasia and growth retardation. Our patient was first noted at the age of 8 months due to pigmentations on skin-folded areas. Initial laboratory tests showed normal fasting glucose (69 mg/dL). Fasting insulin level was severely elevated, up to 554.6 µIU/mL, and c-peptide level was increased, up to 13.81 ng/mL. However, hemoglobin A1c was within normal range (4.8%). He is now 11 yr old. His growth development followed the 5-10th percentile and oral hypoglycemic agents are being administered. The last laboratory results showed insulin 364.1 µIU/mL, C-peptide 4.30 ng/mL, and hemoglobin A1c 7.6%. The boy was a compound heterozygote for the c.90C > A and c.712G > A mutations of the insulin receptor gene, INSR, which are nonsense and missense mutations. In summary, we report the first Korean case of RMS, which was confirmed by two novel mutations of the INSR.
PMCID: PMC3342552  PMID: 22563226
Rabson-Mendenhall Syndrome; Insulin Resistance; Receptor, Insulin; INSR
19.  A study of the relationship between clinical phenotypes and plasma iduronate-2-sulfatase enzyme activities in Hunter syndrome patients 
Korean Journal of Pediatrics  2012;55(3):88-92.
Mucopolysaccharidosis type II (MPS II or Hunter syndrome) is a rare lysosomal storage disorder caused by iduronate-2-sulfatase (IDS) deficiency. MPS II causes a wide phenotypic spectrum of symptoms ranging from mild to severe. IDS activity, which is measured in leukocyte pellets or fibroblasts, was reported to be related to clinical phenotype by Sukegawa-Hayasaka et al. Measurement of residual plasma IDS activity using a fluorometric assay is simpler than conventional measurements using skin fibroblasts or peripheral blood mononuclear cells. This is the first study to describe the relationship between plasma IDS activity and clinical phenotype of MPS II.
We hypothesized that residual plasma IDS activity is related to clinical phenotype. We classified 43 Hunter syndrome patients as having attenuated or severe disease types based on clinical characteristics, especially intellectual and cognitive status. There were 27 patients with the severe type and 16 with the attenuated type. Plasma IDS activity was measured by a fluorometric enzyme assay using 4-methylumbelliferyl-α-iduronate 2-sulphate.
Plasma IDS activity in patients with the severe type was significantly lower than that in patients with the attenuated type (P=0.006). The optimal cut-off value of plasma IDS activity for distinguishing the severe type from the attenuated type was 0.63 nmol·4 hr-1·mL-1. This value had 88.2% sensitivity, 65.4% specificity, and an area under receiver-operator characteristics (ROC) curve of 0.768 (ROC curve analysis; P=0.003).
These results show that the mild phenotype may be related to residual lysosomal enzyme activity.
PMCID: PMC3315624  PMID: 22474463
Hunter syndrome; Mucopolysaccharidosis II; Iduronate sulfatase; Genotype phenotype
20.  Developmental Switch of the Serotonergic Role in the Induction of Synaptic Long-term Potentiation in the Rat Visual Cortex 
Synaptic long-term potentiation (LTP) and long-term depression (LTD) have been studied as mechanisms of ocular dominance plasticity in the rat visual cortex. Serotonin (5-hydroxytryptamine, 5-HT) inhibits the induction of LTP and LTD during the critical period of the rat visual cortex (postnatal 3~5 weeks). However, in adult rats, the increase in 5-HT level in the brain by the administration of the selective serotonin reuptake inhibitor (SSRI) fluoxetine reinstates ocular dominance plasticity and LTP in the visual cortex. Here, we investigated the effect of 5-HT on the induction of LTP in the visual cortex obtained from 3- to 10-week-old rats. Field potentials in layer 2/3, evoked by the stimulation of underlying layer 4, was potentiated by theta-burst stimulation (TBS) in 3- and 5-week-old rats, then declined to the baseline level with aging to 10 weeks. Whereas 5-HT inhibited the induction of LTP in 5-week-old rats, it reinstated the induction of N-methyl-D-aspartate receptor (NMDA)-dependent LTP in 8- and 10-week-old rats. Moreover, the selective SSRI citalopram reinstated LTP. The potentiating effect of 5-HT at 8 weeks of age was mediated by the activation of 5-HT2 receptors, but not by the activation of either 5-HT1A or 5-HT3 receptors. These results suggested that the effect of 5-HT on the induction of LTP switches from inhibitory in young rats to facilitatory in adult rats.
PMCID: PMC3298828  PMID: 22416222
5-HT; SSRI; Citalopram; 5-HT2 receptor; Para-chloroamphetamine
21.  Production of Group Specific Monoclonal Antibody to Aflatoxins and its Application to Enzyme-linked Immunosorbent Assay 
Toxicological Research  2011;27(2):125-131.
Through the present study, we produced a monoclonal antibody against aflatoxin B1 (AFB1) using AFB1- carboxymethoxylamine BSA conjugates. One clone showing high binding ability was selected and it was applied to develop a direct competitive ELISA system. The epitope densities of AFB1-CMO against BSA and KLH were about 1 : 6 and 1 : 545, respectively. The monoclonal antibody (mAb) from cloned hybridoma cell was the IgG1 subclass with λ-type light chains. The IC50s of the monoclonal antibody developed for AFB1, AFB2, AFG1 and AFG2 were 4.36, 7.22, 6.61 and 29.41 ng/ml, respectively, based on the AFB1-KLH coated ELISA system and 15.28, 26.62, 32.75 and 56.67 ng/ml, respectively, based on the mAb coated ELISA. Cross-relativities of mAb to AFB1 for AFB2, AFG1 and AFG2 were 60.47, 65.97 and 14.83% in the AFB1-KLH coated ELISA, and 59.41, 46.66 and 26.97% in the mAb coated ELISA, respectively. Quantitative calculations for AFB1 from the AFB1-Ab ELISA and AFB1-Ag ELISA ranged from 0.25 to 25 ng/ml (R2 > 0.99) and from 1 to 100 ng/ml (R2 > 0.99), respectively. The intra- and inter-assay precision CVs were < 10% in both ELISA assay, representing good reproducibility of developed assay. Recoveries ranged from 79.18 to 91.27%, CVs ranged from 3.21 to 7.97% after spiking AFB1 at concentrations ranging from 5 to 50 ng/ml and following by extraction with 70% methanol solution in the Ab-coated ELISA. In conclusion, we produced a group specific mAb against aflatoxins and developed two direct competitive ELISAs for the detection of AFB1 in feeds based on a monoclonal antibody developed.
PMCID: PMC3834372  PMID: 24278561
Aflatoxin B1; Monoclonal antibody; ELISA
22.  The metabolic syndrome and body composition in childhood cancer survivors 
Korean Journal of Pediatrics  2011;54(6):253-259.
Long-term survivors of childhood cancer appear to have an increased risk for the metabolic syndrome, subsequent type 2 diabetes and cardiovascular disease in adulthood compared to healthy children. The purpose of this study was to investigate the frequency of the metabolic syndrome and associated factors in childhood cancer survivors at a single center in Korea.
We performed a retrospective review of medical records of 98 childhood cancer survivors who were diagnosed and completed anticancer treatment at Samsung Medical Center, Seoul, Korea between Jan. 1996 and Dec. 2007. Parameters of metabolic syndrome were evaluated between Jan. 2008 and Dec. 2009. Clinical and biochemical findings including body fat percentage were analyzed.
A total of 19 (19.4%) patients had the metabolic syndrome. The median body fat percentage was 31.5%. The body mass index and waist circumference were positively correlated with the cranial irradiation dose (r=0.38, P<0.001 and r=0.44, P<0.00, respectively). Sixty-one (62.2%) patients had at least one abnormal lipid value. The triglyceride showed significant positive correlation with the body fat percentage (r=0.26, P=0.03). The high density lipoprotein cholesterol showed significant negative correlation with the percent body fat (r=-0.26, P=0.03).
Childhood cancer survivors should have thorough metabolic evaluation including measurement of body fat percentage even if they are not obese. A better understanding of the determinants of the metabolic syndrome during adolescence might provide preventive interventions for improving health outcomes in adulthood.
PMCID: PMC3174361  PMID: 21949520
Cancer survivor; Metabolic syndrome; Body composition; Fat percentage
23.  Delayed Response of Amylin Levels after an Oral Glucose Challenge in Children with Prader-Willi Syndrome 
Yonsei Medical Journal  2011;52(2):257-262.
Amylin secretion is increased parallel to insulin in obese subjects. Despite their marked obesity, a state of relative hypoinsulinemia occurs in children with Prader-Willi syndrome (PWS). Based on the hypothesis that amylin levels may be relatively low in PWS children, contributing to their excessive appetite, we studied amylin levels after oral glucose loading in children with PWS and overweight controls.
Materials and Methods
Plasma levels of amylin, glucagon, insulin, and glucose were measured at 0, 30, 60, 90, and 120 min after a glucose challenge in children with PWS (n = 18) and overweight controls (n = 25); the relationships among the variables were investigated in these two groups.
Amylin levels were significantly correlated with insulin during fasting and during the oral glucose tolerance test in both groups. Amylin levels between 0 and 60 min after glucose loading were statistically different between the two groups. They were lower in children with PWS than in the controls between 0 and 30 min after glucose loading.
The relatively low levels of amylin, compared to those in overweight controls, during the early phase of glucose loading in patients with PWS, may contribute, in part, to the excessive appetite of PWS patients as compared to the overweight controls.
PMCID: PMC3051207  PMID: 21319343
Prader-Willi syndrome; amylin; child; oral glucose challenge
24.  The Development of Phasic and Tonic Inhibition in the Rat Visual Cortex 
Gamma-aminobutyric acid (GABA)-ergic inhibition is important in the function of the visual cortex. In a previous study, we reported a developmental increase in GABAA receptor-mediated inhibition in the rat visual cortex from 3 to 5 weeks of age. Because this developmental increase is crucial to the regulation of the induction of long-term synaptic plasticity, in the present study we investigated in detail the postnatal development of phasic and tonic inhibition. The amplitude of phasic inhibition evoked by electrical stimulation increased during development from 3 to 8 weeks of age, and the peak time and decay kinetics of inhibitory postsynaptic potential (IPSP) and current (IPSC) slowed progressively. Since the membrane time constant decreased during this period, passive membrane properties might not be involved in the kinetic changes of IPSP and IPSC. Tonic inhibition, another mode of GABAA receptor-mediated inhibition, also increased developmentally and reached a plateau at 5 weeks of age. These results indicate that the time course of the postnatal development of GABAergic inhibition matched well that of the functional maturation of the visual cortex. Thus, the present study provides significant insight into the roles of inhibitory development in the functional maturation of the visual cortical circuits.
PMCID: PMC3034120  PMID: 21311681
Development; GABA; Inhibition; Tonic inhibition; Visual cortex
25.  Effects of Serotonin on the Induction of Long-term Depression in the Rat Visual Cortex 
Long-term potentiation (LTP) and long-term depression (LTD) have both been studied as mechanisms of ocular dominance plasticity in the rat visual cortex. In a previous study, we suggested that a developmental increase in serotonin [5-hydroxytryptamine (5-HT)] might be involved in the decline of LTP, since 5-HT inhibited its induction. In the present study, to further understand the role of 5-HT in a developmental decrease in plasticity, we investigated the effect of 5-HT on the induction of LTD in the pathway from layer 4 to layer 2/3. LTD was inhibited by 5-HT (10 µM) in 5-week-old rats. The inhibitory effect was mediated by activation of 5-HT2 receptors. Since 5-HT also regulates the development of visual cortical circuits, we also investigated the role of 5-HT on the development of inhibition. The development of inhibition was retarded by chronic (2 weeks) depletion of endogenous 5-HT in 5-week-old rats, in which LTD was reinstated. These results suggest that 5-HT regulates the induction of LTD directly via activation of 5-HT2 receptors and indirectly by regulating cortical development. Thus, the present study provides significant insight into the roles of 5-HT on the development of visual cortical circuits and on the age-dependent decline of long-term synaptic plasticity.
PMCID: PMC2997421  PMID: 21165334
5-HT; Development; GABA; Inhibition; LTD; Synaptic plasticity; Visual cortex

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